Motor vehicles are equipped with a windshield wiper device for cleaning or wiping a surface of a windshield. The windshield wiper device includes a wiper motor, a wiper arm and a wiper blade. The wiper arm is connected to a rotating shaft of the wiper motor at its base end and is oscillated by the wiper motor. The wiper blade is separably joined to a distal end of the wiper arm. The wiper blade is positioned on the surface of the windshield by the wiper arm. The wiper blade wipes the surface of the windshield while sliding thereon through oscillating movements of the wiper arm.
The wiper blade has an elongated wiper strip and a frame for holding and supporting the wiper strip in its longitudinal direction. The wiper strip is placed in contact with the windshield surface. The frame may comprise an assembly including a main yoke and a plurality of sub yokes linked to the main yoke. A wiper blade with such a frame is known in the art as “a conventional wiper blade.” A wiper blade, which uses a single frame curving with a certain curvature and having a thin and elongated bar shape as the frame, has been recently used. Such a wiper blade is known in the art as “a flat wiper blade” or “a flat-bar wiper blade.” The flat wiper blade has a height lower than a conventional wiper blade and is subjected to less air resistance when compared to the conventional wiper blade. Further, the flat wiper blade can bring its wiper strip into contact the windshield surface under a uniform load.
The flat wiper blade may be connected to a wiper arm via a connecting unit that is attached to a midway section of a frame and is separably coupled to the wiper arm. Each wiper arm manufacturer has put its own wiper arms for a flat wiper blade in the market. Also, each wiper arm manufacturer or each wiper device manufacturer has put various connecting units, which are configured to be suitable for wiper arms for a flat wiper blade, in the market. Accordingly, there have been known in the art various wiper arms for a flat wiper blade and various connecting units adapted for those wiper arms.
FIGS. 1 to 4 show examples of various wiper arms for a flat wiper blade.
Wiper arms shown in FIGS. 1 and 2 are configured such that their distal ends have a receiving section, concave portions provided at a rear end of the receiving section and a tongue protruding from a front end of the receiving section. These wiper arms are known in the art as “a top lock wiper arm” or “a pinch tab wiper arm.” Korean Patent Application Publication No. 10-2005-0085129 and Korean Patent Application Publication No. 10-2005-0007446 disclose a connection example between a flat wiper blade and a top lock wiper arm. These references teach that a connecting unit is connected to the wiper arm 1, 1′ in such a manner that the connecting unit catches a tongue 13, 13′ at its one end and snap-engages concave portions 14a, 14b, 14a, 14b′ at its opposite end.
A wiper arm shown in FIG. 3 is configured so that its distal end defines an insertion space. This wiper arm is known in the art as “a bayonet wiper arm.” Korean Patent No. 10-725988 discloses a connection example between a flat wiper blade and a bayonet wiper arm. This reference teaches that a connecting unit is fitted to the insertion space in the distal end of the bayonet wiper arm 2 and is thus joined to the bayonet wiper arm.
A wiper arm shown in FIG. 4 is configured such that its distal end portion has a side pin and a clip arm that protrude perpendicularly to a longitudinal direction of the wiper arm. This wiper arm is known in the art as “a side lock wiper arm,” “a side pin wiper arm” or “a slide pin wiper arm.” Korean Patent Application Publication No. 10-2008-0059225 discloses a connection example between a flat wiper blade and a side lock wiper arm. This reference teaches that a connecting unit is connected to a wiper arm in such a manner that a side pin 31 passes through a tubular part of a connecting unit and a clip arm 32 is snap-engaged to the connecting unit.